tbuckley/cabot-search huggingface dataset:
P12.02.A Landscape of surfaceome and endocytome in human glioma is divergent and depends on cellular spatial organization
Authors: V Governa, H Talbot, K Gonçalves de Oliveira, M Cerezo-Magaña, A Bång-Rudenstam, K Forsberg-Nilsson, J Malmström, J Bengzon, C Welinder, M Belting
Journal: Neuro-Oncology (2022)

Abstract Background Cell-surface proteins have a key role in drug development, and tumor cell-surface proteins integrated with the plasma membrane (tumor surfaceome, TS) have attracted considerable attention as targets for immunotherapies in cancer. Checkpoint inhibitor blocking antibodies, antibody drug conjugates (ADCs), and CAR-T cells are all directed at the TS. However, a remaining challenge is the lack of strategies to comprehensively map potential TS target antigens for the design of more rational, individualized treatments. Of particular relevance, ADC and other intracellular drug delivery strategies rely on targets that functionally engage in endocytic internalization. Material and Methods With the aim to address these challenges and to provide insight into the complexity of the TS, we have developed a versatile technology for TS mapping (TS-MAP). As proof-of-concept, we focused on primary brain tumors that remain among the most aggressive forms of cancer, and for which attempts to conquer the most common variant, glioblastoma (GBM) have failed so far. TS-MAP is compatible with primary 3D cultures and intact patient glioma tumors with preserved tissue architecture, and specifically identifies proteins capable of endocytosis as tractable targets for ADCs and other modalities requiring toxic payload internalization. Moreover, we have curated a TS classifier (SURFME) for categorization of bona fide membrane proteins. Results We show how cellular spatial organization (2D vs. 3D) fundamentally transforms the surfaceome and endocytome in glioma with general implications for target screening approaches. The TS-MAP platform was further applied to profile the surfaceome and endocytome landscape in a cohort of freshly resected patient gliomas. We found a highly diverse TS repertoire between patient tumors, not directly associated with grade and histology, which highlights the need for individualized approaches. Conclusions The TS-MAP platform and SURFME classifier should be widely applicable to a variety of brain tumors. Our findings in GBM provide new layers of understanding fundamental to the future development of immunotherapy strategies, as well as new procedures for proteomics-based target identification aimed at a better understanding of how to harness the TS for personalized immunotherapy. Our results reflect the oncogenetic multiclonality and transcriptional diversity of gliomas, which warrants future studies that elucidate how the oncogenetic profile and spatial organization synergize to shape the full complexity of the tumor microenvironment.
P12.09.B Extracellular vesicle derived-miR-146a increases melanoma brain metastasis progression via Notch signalling pathway dysregulation
Authors: E K Rigg, J Wang, Z Xue, T Lunavat, T Hoang, H Parajuli, M Han, G Liu, R Bjerkvig, P Nazarov, N Nicot, S Kreis, C Wurth, H Miletic, T Sundstrøm, X Li, F Thorsen
Journal: Neuro-Oncology (2022)

Abstract Background Melanoma has the highest tropism of any cancer to metastasize to the brain, and 40% of late-stage patients develop brain metastasis. Invasion, survival, and progression of tumors is dependent on the support of the surrounding microenvironment; therefore, modulation of neighboring cells is a key factor in metastasis. Extracellular vesicles (EVs) are important in cell-to-cell signalling, shuttling proteins, RNA and DNA to alter the surroundings into a favorable tumor microenvironment. Our aims were to investigate the role of melanoma brain metastasis (MBM) derived EVs in MBM development to find possible contributing mechanisms to cancer progression for eventual therapeutic targeting. Material and Methods MBM-EVs isolated via sequential ultracentrifugation were injected into mice as a pre-treatment prior to intracardial injection of MBM cells. EVs were co-cultured with normal human astrocytes (NHA) to investigate phenotypic changes. MiRNA sequencing was performed on EVs collected from MBM cells and compared to NHA and melanocytes to determine a candidate miRNA for targeting. In situ hybridization was utilized to evaluate the level of miRNA in clinical patient MBM samples. Functional in vivo validation was performed by injecting miRNA knockout MBM cells into mice. Sequencing of NHA in the presence or absence of target miRNA mimic was used to determine downstream targets. Results Mice primed with EVs had a significant increase in MBM tumor burden, compared to non-primed mice. Co-culture with MBM-EVs resulted in NHA activation in vitro, with increased proliferation, invasion, cytokine production, and upregulation of GFAP. MiR-146a was highly upregulated in MBM EVs, and miR-146a mimics activated NHA. Patient samples had a significant increase in miR-146a expression, compared to healthy brain controls. MiR-146a knockdown in MBM mice models reduced MBM burden and prolonged animal survival. Sequencing of NHA determined NUMB, an inhibitor of the Notch signalling pathway, as a target of miR-146a. Numb and other downstream Notch proteins expression was significantly altered in NHA in the presence of both MBM-EVs and miR-146a. Conclusion In conclusion, EVs are important regulators of MBM and establish tumor-supporting reactive astrocytes by delivery of miR-146a. MiR-146a alters Notch signalling in astrocytes via inhibition of the tumor suppressor gene NUMB. Elevated miR-146a levels in patients suggests a potential clinical intervention is possible via miR-146a targeting.
P11.53.B Efficacy and tolerability of regorafenib in pretreated patients with progressive CNS grade 3 or 4 gliomas
Authors: J Werner, L Wolf, C Tscherpel, E K Bauer, M Wollring, G Ceccon, M Deckert, A Brunn, R Pappesch, R Goldbrunner, G R Fink, N Galldiks
Journal: Neuro-Oncology (2022)

Abstract Background The phase 2 REGOMA trial suggested an encouraging overall survival benefit in glioblastoma patients at first relapse treated with the multikinase inhibitor regorafenib. Here, we evaluated the efficacy and side effects of regorafenib in a real-life setting. Material and Methods From 2018-2021, 30 patients with progressive WHO CNS grade 3 or 4 gliomas treated with regorafenib (160 mg/d; first 3 weeks of each 4-week cycle) with individual dose adjustment depending on toxicity were retrospectively identified. Side effects were evaluated according to the Common Terminology Criteria for Adverse Events (version 5.0). MRI was obtained at baseline and after every second cycle. Tumor progression was assessed according to RANO criteria. After regorafenib initiation, the median progression-free survival (PFS) and overall survival (OS) were calculated. Results The median number of treatment lines before regorafenib was 2 (range, 1-4). The majority of patients (73%) had two or more pretreatment lines. At first relapse, 27% of patients received regorafenib. A total of 94 regorafenib cycles were administered (median number of cycles, 2; range, 1-9 cycles). Grade 3 and 4 side effects were observed in 47% and 7% of patients, respectively, and were not significantly increased in patients with two or more pretreatments (P&amp;gt;0.05). The most frequent grade 3 or 4 side effects were laboratory abnormalities (62%). PFS was 2.6 months (range, 0.8-8.2 months), and the OS was 6.2 months (range, 0.9-24 months). Conclusion In patients with progressive WHO grade 3 or 4 gliomas, predominantly with two pretreatment lines or more, regorafenib seems to be effective despite considerable grade 3 or 4 side effects.
P12.08.A Uncovering the glioblastoma tumor-microenvironment by high-end multiplexing with imaging mass cytometry
Authors: A Anand, D S Harwood, C Bishop, K Todd, R Ellis, R Ellis, F R Poulsen, B W Kristensen
Journal: Neuro-Oncology (2022)

Abstract Background Glioblastoma is one of the most aggressive cancers, and hypoxia plays an essential role in its tumor- microenvironment. Tumor-associated microglia and macrophages (TAMs) have been reported to constitute up to 30 % of the cells, a fraction that is even higher in hypoxic areas. Single-cell mRNA sequencing of glioblastoma tumors has revealed vast heterogeneity, but the spatial aspects are not entirely defined yet. The aim of this study was to uncover differences between the hypoxic and normoxic tumor-microenvironment of human glioblastoma by high-end multiplexing with imaging mass cytometry. Material and Methods A tissue microarray (TMA) with normoxic and hypoxic areas from 4 IDH-wildtype glioblastomas was prepared based on the hypoxia marker hypoxia-inducing factor 1 alpha (HIF1 alpha). The TMA was stained with 18 metal-tagged antibodies covering TAMs, lymphocytes, immune checkpoints, vessels, tumor cells and proliferation. The Hyperion-CYTOF technology was used to ablate the samples and the images were analyzed by MCD viewer, Visiopharm software, and customized R scripts. Results Single-cell analysis of 160 fields covering around 45,000 cells in the glioblastoma microenvironment revealed multiple cellular phenotypes. It was revealed that proliferating TAMs (IBA1+, Ki67+) were more frequent in hypoxia, whereas proliferating vessels (CD34+, Ki67+) were more frequent in normoxia. Additionally, proliferating stem-like tumor cells (OLIG-2+, Ki67+) were more frequent in normoxia regions. Conclusion Our study revealed multiple cellular phenotypes in the glioblastoma microenvironment. The TAMs, endothelial and tumor cell phenotypes revealed may play a critical role in glioblastoma biology however this needs to be elucidated in future studies.
P13.02.B Fully automated segmentation and volumetric measurement of intracranial meningioma using deep learning
Authors: H Kang, J N Witanto, K Pratama, D Lee, K Choi, S Choi, K Kim, M Kim, J Kim, Y Kim, S Park, C Park
Journal: Neuro-Oncology (2022)

Abstract Background Most intracranial meningiomas are small, asymptomatic, and incidentally found tumors. Since the growth of meningioma is the principal indication of treatment, accurate and rapid measurement of the volume of intracranial meningiomas is essential in clinical practice to determine the growth rate of the tumor. It could be useful for the management of meningiomas given their increasing incidence and the wait-and-see policy currently in use for asymptomatic meningiomas. The aim of this study was to develop and validate a computational model for fully automated meningioma segmentation and volume measurement on contrast-enhanced MR scans using deep learning. Material and Methods The retrospectively collected axial contrast-enhanced T1-weighted section images from patients diagnosed with meningioma were manually segmented and used to construct automatic segmentation models with six U-Net- and nnU-Net-based architectures. The performance of each model was evaluated with the Sørensen-Dice similarity coefficient (DSC) with internal (IVS) and external validation sets (EVS), each consisting of 100 independent MRI examinations. Results A total of 12,909 section images from 459 patients were applied for the training (median age 58 [52-66] [IQR]; 385 women [83.9%]). The median tumor volume of the training set was 2.36 cm3. A 2D nnU-Net showed the highest median DSCs of 0.922 and 0.893 for the IVS and EVS, respectively. The nnU-Nets achieved superior performance in meningioma segmentation than the U-Nets. The DSCs of the 2D nnU-Net for small meningiomas less than 1 cm3 were 0.769 and 0.780 with the IVS and EVS, respectively. Conclusion We successfully developed a fully automated and accurate volumetric measurement tool for meningioma using nnU-Net. The volumetry performance for small meningioma was significantly better than that achieved in previous studies. The results of this study are clinically applicable and are expected to be of great use in the management of monitored meningioma patients.
P18.05.A Bevacizumab in atypical and anaplastic meningiomas: the BEMEN study
Authors: G Cerretti, A Bosio, M Maccari, M Padovan, M Caccese, V Zagonel, G Lombardi
Journal: Neuro-Oncology (2022)

Abstract Background meningiomas are the most frequent primary brain tumours. The current standard treatment for atypical and anaplastic meningioma can include surgical resection and radiotherapy. Despite the high rate of relapse no systemic treatment is indicated. Few data are available regarding the effectiveness of bevacizumab (BEV) in this setting. We performed a retrospective analysis investigating the efficacy and safety of BEV in meningioma patients relapsed after receiving surgery and radiotherapy. Gene mutations were also collected Material and Methods we retrospectively analyzed patients treated with off-label BEV at the Veneto Institute of Oncology from July 2019 to February 2022. Major inclusion criteria were histologically-confirmed diagnosis of grade 2-3 meningioma (according to WHO 2016 classification), previous treatment with surgery and radiotherapy, no indication to further surgical reintervention or reirradiation, absence of major contraindications to the use of BEV. Data were estrapolated from local clinical records. Bevacizumab was administered at 10 or 5mg/Kg every 2 weeks (at physician’s discretion) until progressive disease/death or unacceptable toxicity. Kaplan-Meier curves were used to estimate the survival rate; CTCAE v 5.0 was used to estimate treatment-related toxicities; RANO criteria were used for radiological assessment; NGS Foundation One panel was used to examine molecular data Results the median follow up was 13 months (3-30 range). 26 patients were enrolled. Median age was 68 ys (29-84); male pts were 16 (61%); 61% (16 pts) with atypical meningioma, 38.5% (10 pts) with anaplastic meningioma; 27% (7 pts) had underwent 2 or more surgeries; 58% had had 2 or more RT treatments; 96.1% (25 pts) received &amp;lt;2 previous lines of systemic treatment. 77% (20 pts) and 23% (6) received BEV 10 and 5mg/Kg every 2 weeks, respectively. For 61% of patients (16 pts), NGS analyses were available; 62% (10 pts) harboured NF2 mutations (1 patient had a confirmed diagnosis of neurofibromatosis type 2), 23% (6 pts) CDKN2A/2B deletion, 11% (3 pts) PTEN mutation, 8% (2 pts) FGFR mutation, 8% (2 pts) JAK alteration. Overall survival (OS) rate was 82% and 62% at 6 and 12 months respectively; 6 months PFS rate was 83%. 4 patients showed PR, 11 SD, 6 PD, no patient had CR; 5 patients were not evaluable for response. Among evaluable patients the disease control rate (stability+response) was 71% and the objective response rate was 19%. Median PFS and OS were not reached19% (5 pts) experienced CTCAE grade 1 or 2 toxicity, mainly hypertension (4 pts); 1 patient experienced grade 3 hypertension. Conclusion BEV showed very promising activity in recurrent grade 2-3 meningioma. The treatment was well tolerated. BEV should be considered an optimal therapeutic option in this setting of meningioma patients. The NGS results might be useful in identifying targetable mutations in case of further recurrence
P09.07.A Signs and Symptoms in the last days of life of the glioblastoma patients - A Descriptive and Retrospective Study
Authors: M Ferreira, L Vasconcelos, M Lacerda, J Costa
Journal: Neuro-Oncology (2022)

Abstract Background Despite scientific advances to develop techniques for early diagnosis and treatment of glioblastoma, the disease continues to have a remarkably poor prognosis. Studies have shown that in patients with glioblastoma, not only the presence of end-of-life signs and symptoms but also their frequency differs from those in the rest of cancer patients. The complexity of glioblastoma symptoms makes the integration of a palliative care philosophy essential. Objective To identify the main signs and symptoms that occur in patients with glioblastoma in their last seven days of life in a neuro-oncology ward. Material and Methods This was a descriptive and retrospective study regarding the signs and symptoms in the last seven days of life of patients with glioblastoma who were admitted to the neurology ward of a national oncology reference center. The patients were admitted after neuro-oncologist consultations between 2019 and 2020. The data collection instrument used was based on the document “The Last Hours of Living”. Confidentiality of the participants was guaranteed, and authorization was obtained from the institution’s ethics committee. Results The sample had 17 patients (13 men and 4 women), with an average hospital stay of 17.3 days. The men and women had average ages of 61.8 and 63 years, respectively. Clinical and nursing records revealed that the most prevalent signs and symptoms were “decreased level of consciousness” (94%); “rare and unexpected events” (94%); “respiratory dysfunction” (88%); and “loss of ability to swallow” (76%). In the last seven days of life, the approximate times of presentation for these signs and symptoms were: decreased level of consciousness, 6 days; rare and unexpected events, 2 days; respiratory dysfunction, 3 days; and loss of ability to swallow, 6 days. Support was requested from the in-hospital palliative care support team for 76.4% of patients. Conclusion The identification of reduced level of consciousness and alterations in swallowing as the most prevalent symptoms is consistent with the findings of previous studies. The prevalence of rare and unexpected events (such as fever, myoclonus and seizures) aligns with previous studies that indicated a difference in the signs and symptoms presented by patients with glioblastoma in the last days of life and patients with other oncological diseases. In this sense, the instrument used for data collection may not be the most appropriate for the population with primary central nervous system tumors. The decreased level of consciousness and impaired communication can complicate the assessment of signs and symptoms, such as pain, nausea, anxiety and depression. It is essential to conduct research studies with more representative samples. The recording of the signs and symptoms presented, as well as interventions and the evaluation of their effectiveness, are essential to ensure the quality of end-of-life.
JS09.7.A Reirradiation for recurrent high grade glioma (HGG) patients: results of a single arm prospective phase 2 study
Authors: E Clerici, P Navarria, L Bellu, F Pessina, M Simonelli, B Marini, S Bianchi, M Scorsetti
Journal: Neuro-Oncology (2022)

Abstract Background Standard of care for recurrent high grade glioma (HGG) is missing. Several treatment options have been investigated including re-irradiation (re-RT). Results are promising but provided by retrospective studies. We designed a single arm prospective phase II study aiming to evaluate efficacy, and toxicity of re-irradiation. Material and Methods Adults patients with good performance status, HGG diagnosis reclassified according to the new 2021 fifth edition WHO CNS classification, an interval time (IT) from previous RT ≥ 6 months were included. Outcome was evaluated by MRI imaging at 1 month, and every 3 months thereafter. Toxicities were evaluated in terms of radionecrosis occurrence, and neurocognitive status. Results Ninety recurrent HGG patients were treated, 11 oligodendroglioma grade 3, 18 astrocytoma grade 3 and 4, and 61 glioblastoma grade 4. The median age was 54 years, and majority had KPS 90-100. The median IT between first-RT and re-RT was 24 months. Re-surgery has been performed in 56.6%, and chemotherapy in 53.3%. The median follow up time was 64 months; median overall survival (OS) time,1,2,3-year OS rates were 17 months (95%CI 14-19), 66.7%±4.9, 32.6%±5.0, and 22.2 ± 4.7. Prognostic factors impacting on survival were age (p = 0.0154), IT between first RT and re-RT (p = 0.0051), glioma grade (p = 0.0090), and IDH status (p = 0.0001). Radionecrosis grade 2-3 occurred in 9 (10%) patients; neurocognitive functions remained stable until disease progression. Conclusion Re-RT proved to be a safe and feasible treatment option with low toxicity. Younger patients with grade 3 IDH mutated gliomas, and a longer IT had the better outcome.
P06.08.B Radiation therapy enhances anti-tumor activity of a MET CAR T-based immunotherapy for glioblastoma
Authors: L Hovhannisyan, D M Aebersold, M Medova, A F Ochsenbein, J Maher, Y Zimmer
Journal: Neuro-Oncology (2022)

Abstract Background Glioblastoma is the most frequent primary brain tumor with dismal prognosis after standard treatment with surgery, and chemoradiation (the Stupp protocol). After a decade of failed clinical trials, tumor-treating fields have been first to show the added benefit of improved overall survival compared to the Stupp protocol (20.9 months vs 16.0 months). However, GBM remains a devastating disease, with almost inevitable recurrence, and limited options for second-line therapy. Radiation therapy (RT), is a standard therapy option for GBM, and it is used in most GBM cases affecting tumor through induction of DNA-damage. Recently, RT has been investigated as a mediator of T cell-based therapies in the context of immunosuppressive GBM microenvironment. The findings have shown promise in combination of T cell-based therapies, such as chimeric antigen receptor (CAR) T cell therapies, in improving the tumor infiltration, and penetration with immune cells. MET is a relevant oncogene in the context of GBM, being involved in stem-like properties, radiation response and resistance․ Hence, MET appeared to be a plausible target for combination with RT. In our research, we use MET-targeting CAR T cells (MET-CAR T cells) combined with radiation, and hypothesize synergistic interaction for GBM treatment. Material and Methods We used adherent (2D) and stem-like (3D) human GBM cell lines with different levels of MET expression. For MET-CAR T cell generation we did retrovirus-mediated transduction of activated human T cells and sorted the CAR-positive cells. We co-cultured MET-CAR T cells with GBM cells with or without RT, and assessed the killing and cytokine production in CAR T cells. Results Our results indicated that 5Gy radiation combined with MET-CAR T cells increases their potential in tumor cell killing. We observed increased CAR T cells effect at lower CAR T to target cells ratios when combined with radiation, even when radiation treatment did not lead to a significant decrease in viability. This phenomenon was similar across different types of cell lines (adherent, stem-like), different levels of MET expression, and different sensitivity to CAR T cells. We investigated the underlying mechanisms via intracellular cytokine measurement. We observed the most prominent response in TNF-α-expression. We also observed an increase in Granzyme B expression in co-culture with some of the GBM cell lines, especially in CD8+ subpopulation of CAR T cells. IFN-gamma expression increased in some adherent glioma cell lines but not in stem-like cell lines. Conclusion In conclusion, our data demonstrates the potency of MET-CAR T cells against GBM, and increased efficiency when combined with radiation. The suggested mechanism is the increased activation of T cells in TNF-α-dependent-manner. To validate these results we are testing our setup in an orthotopic mouse GBM model.